Printing press plate clamping means for prebent wrap around printing plates of soft material



Jan. 9, 1962 H. J. LUEHRS 3,016,010 PRINTING PRESS PLATE CLAMPING MEANSFOR PREBENT WRAP AROUND PRINTING PLATES 0F son MATERIAL Filed Aug. 20,-1959 4 Sheets-Sheet 1 INVENTQR. HA N5 \1 LUEHR- llrlelilllla'xlllqlllmlll momma Jan. 9, 1962 H. JQ'LUEHRS 3,016,010 PRINTING PRESSPLATE CLAMPING MEANS FOR PREBENT WRAP AROUND PRINTING PLATES OF SOFTMATERIAL Filed Aug 20, 1959 4 Sheets-Sheet 2 INVENTOR. HANS d. LU EHR62mm 0 ATTORNEYS Jan. 9, 1962 H. .1. LUEHRS 3,016,010 PRINTING PRESSPLATE CLAMPING MEANS FOR PREBENT WRAP AROUND PRINTING PLATES OF SOFTMATERIAL 4 Sheets-Sheet 3 Filed Aug. 20, 1959 INVHVTOR. HAN5 J. LUEHR$ 61 M f-M ATTOBM'YS Jan. 9, 1962 H. J. LUEHRS 3,016,010 PRINTING PRESSPLATE CLAMPING ms FOR PREBENT WRAP AROUND PRINTING PLATES OF SOFTMATERIAL Filed Aug. 20, 1959 4 Sheets-Sheet 4 INVEN OR ff d Mwwn/ flATTORNEYS Patented Jan. 9, 1962 PREZS PLATE CLAMPING MEANS F81 PQEBENTAP ARDUND PRENTING PLATES GE SOFT MATERIAL Hans J. Luehrs, Westerly,R.I., assignor to The Cottrell Company, Westerly, R.I., a corporation ofDelaware Filed Ann. 20, 1959, Ser. No. 834,987 6 Claims. (Cl. 101415.1)

The object of my invention is to provide a clamping means suitable forprinting plates of relatively thin material wherein the plate clampingmechanism is adapted for location in a cylinder bore which communicateswith a longitudinal circumferential cylinder slot in such a way that nooverhanging bolted filling in pieces are required to round out thecircumference of the cylinder.

Another object of my invention is to provide a plate clamping means ofthe character described by which predetermined plate tension will bemaintained, under substantially all conditions, across the width of eachplate.

Another object is to furnish means for quickly clamping a prebentprinting plate or plates to the cylinder in predeterminedcircumferential location.

Another object is to provide a plate clamping means for wrap-aroundprebent printing plates which will secure the plates to the cylinder soas to leave a minimum lateral printing margin.

A still further object is to provide a structure of the characterdescribed wherein the plate clamping means are of a design such that themaximum rigidity and strength of the plate cylinder and its journals mayeffectively be retained.

Broadly, my invention comprises a printing plate clamping assembly forflexible wrap-around prebent printing plates which is arranged forpartial rotation within the cylinder and which exerts both a clampingpressure on the lewling end of the pl te and a positive tensioningcontact with a perforated tail end of said plate wherein the ele mentsengaging the tail end of the plate and clamping the lead end of theplate are spring biased to insure a uniform predetermined tensionthroughout the width of the plate.

Practical embodiments of my invention are illustrated in theaccompanying drawings in which:

FIG. 1 represents in plan view, partially broken away, a prebent platetensioned on the plate cylinder.

FIG. la represents a plan view, partly broken away, of the left end ofthe plate cylinder.

FIG. 2 represents a section taken on the line 11-11 of FIG. 1 looking inthe direction of the arrows.

FIG. 3 represents in perspective a fragment of printing plate prebentand having its tail end adapted for engagement by spring loaded plateengaging devices to tension the plate to the cylinder.

FIG. 4 repersents a partially detailed section taken on the line lII-IIIof FIG. I, looking in the direction of the arrows, showing the leadingplate edge being inserted and registered within the cylinder slot.

FIG. 5 represents a view similar to FIG. 4, except that the leadingplate edge has been fitted to the cylinder and the plate clampingmechanism has been partially rotated in a counter clockwise direction.

FIG. 6 represents a view similar to FIGS. 4 and 5 but showing the plateclamping mechanism as further rotated in a counter clockwise directionand with the trailing edge of the plate registered in the cylinder slot.

FIG. 7 represents a view similar to FIGS. 4, 5 and 6 with the plateclamping means rotated still further in a counter clockwise direction totension the plate on the cylinder for the printing operation and byengaging the leading plate edge through the plate tail edge perforationsto clamp said leading plate edge to the cylinder.

FIG. 8 represents a detail partially in section taken on the lineVIII-VIII of FIG. 6, looking in the direction of the arrows, showing thespring biased plate engaging clamps mounted on their rotatable shaft,and;

FIG, 9 represents a detail section, on an enlarged scale, partiallybroken away, taken on the line lX-IX of FIG. 2 looking in the directionof the arrows.

Referring to the drawings, in which the parts are given the samenumerals in the respective figures in which they appear, the usual platecylinder is denoted by 1, its bearers by 2 and 3 and the cylinderjournals by 4 and 5, it being understood that this cylinder is mountedfor rotation in the press frame (not shown) in the usual manner Prebentplate 6 which, in the present instance, is of a soft material such aszinc, is provided at its trailing edge with suitable clamp receivingmeans such as perforations, denoted collectively by 7, the latter beingequally spaced across the plate tail to receive ends 28 of the plateengaging devices 18.

It will be noted that the cylinder 1 is circumferentially bored at 8 andslotted at 9 so that both the bore and slot lie parallel to thelongitudinal axis of the cylinder 1 and extend across the circumferencethereof between the bearers. Slot 9 communicates throughout its lengthwith bore 8.

Located within the bore 8 is a plate clamping assembly consisting ofactuating shaft 10 and collar assemblies 11 and 12 which are springloaded as shown in FIG. 4 and turnably mount-ed on said shaft.

Said shaft 10 is provided with a key 13 and sectional pieces 14 boltedthereto as shown in FIG. 4. When the shaft 10 is in its inactiveposition, springs 15 urge the collar assemblies 11 and 12 against stops16, or pieces 14 as shown in said FIG. 4.

The collar assemblies 11 and 12 are also provided with leaf springs 17as shown in FIG. 8 which bias the plate clamping mountings denotedcollectively by 18, into position where their projections 28 enterperforations 7 in the trailing edge of the plate 6 and extendtherethrough into engagement with the surface of the plate leading edge22 which was previously inserted through the cylinder slot 9 andregistered against a stop 25 on collar section 12 (as shown in FIG. 4).

In order to operate the plate clamping assembly a worm and wheel drive,for shaft 10, as shown in FIGS. 2 and 9, is provided at one end of thecylinder 1 and mounted adjacent the bearer 3 (as shown in FIG. 1). Thisdriving means consists of the turnable shaft 10 carrying the gear 19,said gear being operatively engaged by a worm 20 mounted at right anglesthereto in the usual manner, as shown in FIG. 9. This assembly ismounted by suitable screw bolts denoted collectively by 21. A recess 29to receive a hand tool (not shown) for turning the worm 20 is providedso as to be accessible at one end of the cylinder.

The operation of my device is as follows: the leading plate edge 22 isinserted through the cylinder slot 9 and gear 19 mounted on said shaft.

registered against the stop 25 of member 12 as shown in FIG. 4. Theprebent plate 6 is then pressed by hand or other suitable means againstthe surface of cylinder 1 and wrapped there-around. Then, by theinsertion and actuation of a wrench (not shown) the worm 29 is turnedand thereby rotates the shaft in a counter clockwise direction throughthe coaction of said worm 20 with the 7 With the clamping mechanism inthe position illustrated in FIG. 6 the trailing edge 27 of plate 6 isinserted through the cylinder slot 9 to a position where the plateengaging ends 28 of devices 18 will be urged by their springs to enterthe recesses or perforations 7 in the trailing edge 27 of plate 6, saidedge 27 being registered against stop 26. By means of a wrench or othersuitable tool turning worm 20 engaged with gear 19 causes the shaft 10to be turned further in a counter clockwise direction so that the plateis securely tensioned to the cylinder 1 by having its trailing edge 27drawn into the cylinder slot 9 by said devices 18 to a position shown inFIG. 7. This causes the plate engaging devices to not only tension theplate to the cylinder but also to engage the available interior surfaceof the plate leading edge whereby the plate is held to the cylinderunder tension as well as by being clamped and held, at its leading edgesection, against the inner surface of the cylinder bore 8.

It will be noted that the insertion of both the leading and trailingedges into the cylinder slot is limited as by a stop 25 for the leadingedge end 22, and stop 26 for the plate trailing edge 27 which stopsserve to square the leading and trailing edges of the plate intoparallelism with the longitudinal axis of the cylinder.

Since the leading and trailing edges of the prebent plate are squaredinto parallelism with the longitudinal axis of the cylinder, as abovedescribed, any subsequent adjustments must be provided by equipping thecylinder itself with lateral and circumferential adjustment (not shownin the present application) as is well known in the art.

Subsequently, all the collar assemblies by means of their springs 15,and their spring mounted plate clamping mountings will individuallytension the plate throughout its entire width. It will be understoodthat the amount of tension applied to the plate must necessarily bewithin the limits of the plate.

It will be understood that When the cylinder is provided with two platesside by side, two independent clamping mechanisms'may be provided, thedrives therefor being located at opposite ends of the cylinder andoperable therefrom,

The left-hand end of the cylinder 1 is plated as shown in FIG. la sothat the shaft 10 may be driven from either end; the second plate 6abeing clamped similarly to plate 6; A screw 27a accomplishes what screw21 does at the other end of the cylinder and 29a is a tool receivingsocket.

Since it is evident that various changes may be made in theconstruction, form and arrangements of the several parts withoutdeparting from the spirit and scope of my invention, I do not intend tobe limited to the particular embodiment herein shown and describedexcept as set forth in the appended claims.

What I claim is:

1. Plate clamping mechanism for flexible wrap around printing platescomprising the combination of a rotary bringing the plate clamping andtensioning means into operative engagement with both plate ends, thesaid last named means being located in the cylinder bore for clampingand tensioning the plate to the cylinder including a turnable shaftmounted in said bore, spring biased collars turnably mounted andsupported on said shaft against deflection, and spring biased plateengaging means mounted on said collars.

2. The combination according to claim 1, in which the plate tail isperforated and the clamping and tensioning means are located to entersaid perforations and proiect therethrough into clamping engagement withthe leading edge of the plate.

3. The combination according to claim 1, in which means for bringing theplate clamping and tensioning means into operative engagement with theplate ends are located at both ends of the cylinder.

4. Plate clamping mechanism for wrap around printing plates comprisingthe combination with a rotary printing cylinder of a longitudinalcircumferential slot across the cylinder and parallel with thelongitudinal axis of same, a longitudinal bore parallel to andcommunicating with said slot, a plate wrapped around said cylinder andmeans located in the cylinder bore for tensioning said plate on thecylinder in printing position, said last named means comprising alongitudinal shaft mounted in said bore, a plurality of spring biasedcollars mounted on said shaft, stops on said collars for registering theleading and trailing plate ends, spring biased plate engaging devicesnormally urged outwardly against the interior wall of the cylinder bore,and exterior means for actuating said shaft to bring said devices intoplate end engagement whereby the plate is tensioned on the cylinder andthe plate leading edge is pressed by said devices against an interiorwall of said cylinder bore.

5. Plate clamping mechanism for wrap around printing plates comprisingthe combination with a rotary printing cylinder of a longitudinalcircumferential slot across the cvlinder and parallel with thelongitudinal axis of same, a longitudinal bore parallel to andcommunicating with said slot, a prebent printing plate wrapped aroundsaid cylinder and means located in the cylinder bore for removablytensioning said plate on the cylinder in printing position, said lastnamed means comprising a longitudinal shaft mounted in said bore, atleast one spring biased collar mounted on said shaft, at least one stopon said collar for successively registering the leading and trailingplate ends, spring biased plate engaging devices normally urgedoutwardly toward the interior wall of the cylinder bore, and exteriormeans for actuating said shaft to bring said devices into plate endengagement whereby the plate is tensioned on the cylinder and the plateleading edge is pressed by said devices against an interior wall of saidcylinder bore, said exterior means comprising a gear on said shaft, aworm in operative engagement therewith and means for actuating saidworm, the latter means including a tool receiving recess adapted toreceive a hand tool therein for turning said worm.

6. Plate clamping mechanism for wrap around printing plates comprisingthe combination with a rotary printing cylinder of a longitudinalcircumferential slot across the cylinder and parallel with thelongitudinal axis of same, a longitudinal bore parallel to andcommunicating with said slot, a prebent printing plate wrapped aroundsaid cylinder and means located in the cylinder bore for tensioning saidplate on the cylinder in printing position, said last named meanscomprising a longitudinal shaft mounted in said bore, at least onespring biased collar mounted on said shaft, at least one stop on saidcollar for successively registering the leading and trailing plate ends,spring biased plate engaging devices normally urged outwardly againstthe interior wall of the cylinder bore, and exterior means for actuatingsaid shaft to bring said devices into plate end engagement whereby theplate is tensioned on the cylinder and the plate leading edge is 5pressed by said devices against an interior wall of said cylinder bore,said exterior means comprising a gear on said shaft, a worm in operativeengagement therewith and means for actuating said warm, the latter meansincluding a tool receiving recess adapted to receive a hand tool 5therein for turning said Worm.

References Cited in the file of this patent UNITED STATES PATENTS2,109,152 Meisel Peb.22,1938 10 Neilscn Apr. 7, 1942 Friesz et a1 July20, 1954 Leeberg July 12, 1955 Hantscho Aug. 25, 1959 FOREIGN PATENTSGermany Aug. 30, 1935 Switzerland Oct. 16, 1950

